Similar changes will need to be made here too, but the series connection really reduces the SOA burden on the drivers and outputs.

What you really should do is order a service manual for a Crest 8000, one of the best pro sound amps that has been around for a long time. The schematic looks just like the Super Leach with some extras, inrush current limiting, relay and DC sense, things of that nature.

I'm closing this thread. 256 volts and a huge transformer is dangerous and also something only for experts in amplifier design. If you don't know so much about the difficulties I think you should try other solutions.

Reconsider your need for power.127 volts can give you 2000 watts. Do you need that?

Most drivers [even the big ones with 4" or 5" voice coils] start to 'sweat' when driven with 600W just before clipping and in my experience 1200W is the practical limit for 18" or 21" drivers

To get 1200W into 8 ohms +-150V rails would be required but with so high rails also class G or H operation [ie: +-50V +-100V +-150V] is required in order to mantain dissipation and power consumption in reasonable numbers and to keep under control the costs and the number of output devices required [look for QSC schematics, 'EX4000' model may be a reference]

In my oppinion, if you want more SPL and have reached 500W, the best solution is not to add more power but to add more drivers and more amplifier channels. Increasing the number of drivers also increases efficiency so theoretically dual drivers with 500W + 500W produce as much SPL as a single driver with 2000W

Proper horn loading may also boost the SPL by 10dB, and this is a serious thing since it means that 100W of input in a horn loaded system may produce as much SPL as 1000W of input in a direct radiating system

If you want to produce some SPL outdoors, the absolute minimum number of bass drivers or bass horns to place toghether is four [mono bass or four at each side] due to spatial loading issues. Groups of less units will suffer from very poor efficiency